Ors to tfie farbenfabrikek



' invented a new and useful Improvement in diazo compound of amidonaphthaline azo- TATES RICHARD LAUGH AND CARL KREKELER, OF EIJBERFELD, GERMANY, ASSlGl ATENT sures.

OBS TO THE FARBENFABRIKEN, VOR-MALS FR. BAYER & 00., OF SAME PLAfiE.

B L U E- G R E E N AZO DYE.

SPECIFICATION forming part of Letters Patent No. 464,775, dated December 8, 1891.

Application filed July 17, 189].

To all whom, it may concern..-

Be it known that we, RICHARD LAUGH and CARL KREKELER, chemists, (assignors to the FARBENFABRIKEN, voRnALs Fa. BAYER d: (10., at Elberfeld,) subjects of the King of Prussia, residing at Elbert'eld, Germany, have the Manufacture of Dye-Studs, of which we give in the following a clear and exact description.

Our invention relates to the production of a new bluish-green coloring-matter for dyeing wool, of the formula OH H...

.l'lli. v t' n lvzx ig ihnzx--( o on (OONa eo Na by combining one molecular proportion of the salicylic acid with one molecular proportion of dihydroxynnphthaline inonosulpho acid we described in Letterslatentk'o. 444,679, dated January 13, 1891.

\Ve proceed ast'ollows: kilos, by weight, 0t amidosalicylic acid are dissolved in water, and, after having been cooled by ice, mixed with a watery solution of seven kilos, by weight, of sodium nitrite. On the addition of inuriatie acid the diazo compound precipitated as a fine crystalline powder, and after about halt an hour the diazo compound has completely separated. The latter is there upon: filtered off and, without having been dried, under continuous stirring mixed with a hydrochloric-acid solution of 14. 3 parts, by weight, of alpliamaphthylamine. ()n theaddition of sodium acetatethe production of a dyestnit immediately begins, and is finished when the liquid, after standing for about twelve hours, is heated for a short time to about centigrade. 'lhe thus-formed amidoazo compound is filtered oil in order to remove the uncomblned alpha-naphthylamine, then dissolved in diluted alkali, and this solution, after the addition of seven kilos, by weight, of sodium nitrite, is acidulated with diluted hydrochloric acid under continuous stirring. After about one hour a diazo product has emu:

Serial No. 399,846. (Specimens) is thereupon added to an acetic-acid solution of about 26.2 kilos, by weight, of dihydroxynaphthaline monosulpho acid of the Letters Patent No. 144.,670, dated January 13, 1891, in the presence of an excess of sodium acetate. The production of the dye-stuff is easily to be completed by heating fora short time at about 50 centigrade. The thus-formed coloringmatter, of the formula 011 Oil represents, after having been neutralized with alkalis, filtered 01f, and dried, a bluish-black powder, which with diiiiculty dissolvesin cold water, more easily in hot water with blueviolet color, likewise in solutions of sodium carbonate with blue violet, in solutions of sodium hydroxide and ammonia with almost pure blue color. In concentrated sulphuric acid it is soluble with deep-green color, that is altered by addition of water into a pure blue, the whole dye-stud gradually separating in L dark-blue flakes. In the same form the dye stuff is also precipitated when its water solutions are mixed with mineral acids in excess.

'lhe abovedescribed coloring-matter dyes wool inordanted with chromium salts in bluish-green shades very fast against sunlight, soap, and milling.

Having thus described our invention and in what manner it may be carried out, what we claim as new, and desire to secure by Letters Patent, is

formula COONa SO Na, which is in a dry State a bluish-black powder, dissolving with difiiculty in cold water, more easily in hot water with blue-violet color, also readily in solutions of alkaline with almost pure blue color; it is soluble in concentrated plctely separated as a black precipitate. It

sulphuric acid with darkgreen color, that ICC ' azo-salicylic acid with one molecular proporis altered by addition of water into a pure blue, while the. Whole dye-stuif gradually separates in dark-blue flakes; it is capable of dyeing wool mordant-ed with chromium salts in bluish-green shades very fast against sunlighhsoap, and milling.

2. The process for producing the new dyestufi, as hereinbefore described, which consists in combining one molecular proportion of the diazo compound of amidonaphthaline tion of dihydroxynaphthaline monosulphonic acid in the presence of sod 1m acetate.

In testimony whereof we have signed our names to this specification in the presence of 15 two witnesses.

RICHARD LAUGH. CARL KREKELER.

Witnesses: I

WM. ESSE'MOLIN, RUDOLPH FRIQKEL. 

